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Metastability and Eye Movements: A Dynamical‑Systems Interpretation

  1. Why metastability is a natural language for gaze behavior The idea that perception, attention, and neural activity evolve through transiently stable states has deep roots in cognitive science and neuroscience. Concepts such as attractors , basins , noise‑induced transitions , and escape times appear in work on perceptual switching, decision‑making, and neural population dynamics (Kelso, 1995; Rabinovich et al., 2008; Deco & Jirsa, 2012). Eye movements, especially the alternation between fixations and saccades ,   fit remarkably well into this metastable picture. The Freidlin–Wentzell theory of rare events (Freidlin & Wentzell, 2012) provides a rigorous mathematical language for these intuitions. 2. Fixations as metastable states  Consider the gaze position X t as the state of a stochastic dynamical system. During a fixation the  gaze remains confined to a small region, microsaccades and noise generate small fluctuations, and the gaze tends to return...

Alzheimer's disease: study on substances to slow disease

The results obtained in pre-clinical researchers from the University of Modena and Reggio Emilia (Italy) open hopes in the treatment of disease: hydrogen sulfide and the melanocortin would be able to slow the progression of the Alzheimer's  disease. From the results of research done by the Modena group, coordinated by Salvatore Guarini, Professor of Pharmacology at the Department of Biomedical Sciences, Metabolic and Neuroscience, hydrogen sulphide and melanocortins are able to slow the progression of Alzheimer's disease. Alzheimer's disease is the most common cause of dementia, and without effective treatment, one of the major causes of disability and mortality. Alzheimer's disease is usually diagnosed after the age of 65, while the form of Alzheimer's disease less prevalent, that family or genetic disease, can occur much earlier. The interest of the international scientific community for the originality of the results and the methodological rigor of the s...

The U.S. GDP Growth Accelerates in Second Quarter, doesn't it ?

The  Bureau of Economic Analysis  ( BEA ) asserts [ here ] :  " Real gross domestic product (GDP) increased 1.7 percent in the second quarter of 2013 after increasing 1.1 percent in the first quarter, according to the “advance” estimate released today [July 31, 2013] by the Bureau of Economic Analysis ( BEA ). "  One would say that the reported growth of the annualized estimate of the U.S. GDP (+1.7%) outperforms the expected result.  We recall that the official GDP is calculated at constant prices, i.e, by applying a deflator to the current values.  In practice, it takes account of the specific rate of inflation in the components of GDP. Obviously the lower the GDP deflator the higher the GDP . Well, the deflator used by the BEA for the second quarter was a tiny +0.71% whilst in the first quarter it was +1.7% and in the last 14 quarters, the U.S. GDP deflator was +1.75% on average. It sounds a bit odd ! If the GDP deflator were wha...

Ocular-Motor Profile and Effects of Memantine in a Familial Form of Adult Cerebellar Ataxia with Slow Saccades and Square Wave Saccadic Intrusions

This study [ here ] suggests that  memantine may have some general suppressive effect on saccadic intrusions , including both  square wave intrusions (SWI)   and  macrosaccadic oscillations  ( MSO), thereby restoring the capacity of reading and visual attention in these and in other recessive forms of ataxia, including Friedreich’s, in which saccadic intrusions are prominent.     Two patients ( two sisters with identical phenotype ) with an unrecognized, probably recessive hereditary form of adult-onset cerebellar ataxia clinically characterized by axonal sensory neuropathy, cerebellar atrophy, slow saccades and prominent  square wave intrusions , have been treated  with the drug memantine,  which is an uncompetitive antagonist of the NMDA-receptor (NMDAR)  [1] . The aim was to suppress frequent and large saccadic intrusions.  Fixation instability due to saccadic intrusions is a feature of autosomal recessive spinoce...

PERSPECTIVES ON DETROIT

The failure of Detroit can not go unnoticed. The main causes and potential side effects have been reported [ here ] and [ here ] . Let's see now the point of view of professor Stephen Cohen .   Stephen Cohen teaches economics at the University of Berkeley [1] . Specialist of urban economy and territory, after the failure of the city of Detroit answers some questions at the information portal Liberation.fr [ here ] . 1. What is the importance of this failure of American scale? It 's the worst failure of a local authority ever made in the United States from the years of the Second World War. The debt of the city is 20 billion dollars. A considerable sum, but it is not a surprise. Once Detroit was the fourth largest city in the country. Since 1950, has lost half of its inhabitants. Today it has 700,000, versus 1.8 million over fifty years ago. They were the poorest, with a population of color equal to 80%. The real estate industry has collapsed, as well as tax reve...

SIDE EFFECTS OF THE FAILURE OF DETROIT

The financial failure of the city of Detroit [ here ] will also have consequences on some European banks, exposed towards the debt contracted by the American metropolis. Among the banks involved there is also UBS : in 2005 the bank was handling the sale of $ 1.4 billion of municipal bonds. Operations conducted on behalf of the administration of Detroit, to enable it to finance its pension fund. Similar operations involving other banks - for a total of another billion dollars - and these include many institutions that already live in conditions of difficulty. As in the case of the "bad bank" of Hypo Real Estate , which is the most exposed with $ 200 million, to Commerzbank , which owns a total of 4.5 billion euro in American local governments, or Deutsche Bank , not involved however excessively.

DETROIT BANKRUPTCY

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And so Detroit has gone bankrupt.  The news of the failure of a (former) major American city, an event of far greater importance than that of the city of San Bernardino (CA), the Boise County (IH) or Jefferson County (AL). The greater severity of the failure of Detroit stems not only from total size of the debt, but also the origin of the structural debt: while in other cases the trigger for the crisis was a limited negative event, such as severe errors in the management of the debt or investment, in the case of Detroit instead the causes are structural and inherent in the evolution of the city itself . Demographic decline . The city went from having 1,849,000 inhabitants in 1950 to just over 700,000 today. Pretty much the city has had a reduction of two thirds of the inhabitants. Why do people have fallen so substantially? The City's economy was based on a  single industry . Detroit was the city of cars, home of the three majors of the automotive industry and a ...

The coffers of the central banks are empty. The collapse of the price of gold has been planned

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Eric Sprott , fund manager [1] , argues that the current collapse in the value of gold has been long planned by the central banks of the United States and Europe, to take advantage of low prices and fill bullion safes now empty. According to Sprott, the coffers of Western central banks are empty and since the news should not have been disclosed, here that was organized a reduction in demand for gold in a very short period of time. At first brokers and western commercial banks have advised clients to sell gold. The institutions themselves have held their positions 'short' bearish on the COMEX. When bidding for the benchmark price of the precious metal has surged, the statements about a reduction in the extent of monetary easing measures by the helmsmen of the lead institutions did the rest, driving down the prices.  Speculators such as hedge funds have opened an avalanche of short positions, futures markets have suffered a blow on the metal and gold stocks are at all-time lo...

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